Radio-frequency module and communication apparatus

ABSTRACT

A radio-frequency module including a mounting substrate that has mounting faces opposed to each other; a PA that is mounted on the mounting face, that is a radio-frequency component, and that has an emitter terminal; a through electrode that is connected to the emitter terminal of the PA and that passes through the mounting faces of the mounting substrate; and a ground terminal connected to the through electrode.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation application of PCT International Application No.PCT/JP2019/009579 filed on Mar. 11, 2019 designating the United Statesof America, which is based on and claims priority of Japanese PatentApplication No. 2018-057103 filed on Mar. 23, 2018. The entiredisclosures of the above-identified applications, including thespecifications, drawings and claims are incorporated herein by referencein their entirety.

BACKGROUND 1. Field of the Disclosure

The present disclosure relates to a radio-frequency module and acommunication apparatus.

2. Description of the Related Art

In mobile communication apparatuses, such as mobile phones, the numberof circuit elements composing radio-frequency (RF) front end circuitsare increasing particularly with development of multiband technologies.

International Publication No. 2005/078796 describes an electroniccomponent (circuit module) in which circuit elements composing aradio-frequency front end circuit are mounted on both faces of amounting substrate. Passive chip components are mounted on a secondmounting face, among two mounting faces of a dual-side mounted coresubstrate, which are opposed to each other, and active chip componentsare mounted on a first mounting face opposite to the second mountingface. The second mounting face is at the side where external terminalelectrodes are arranged. With the above configuration, the high-densityand compact circuit module is capable of being provided, compared with acircuit module in which the circuit elements are formed on a single-sidemounted substrate.

SUMMARY

When the circuit module disclosed in International Publication No.2005/078796 is applied to a radio-frequency front end circuit, atransmission power amplifier that outputs a high-power radio-frequencysignal is applied as an active chip component. In this case, forexample, since high current flows through an emitter portion of thetransmission power amplifier, it is necessary to ensure that a heatradiating unit from the circuit module to an external substrate isprovided.

However, in the circuit module disclosed in International PublicationNo. 2005/078796, since the active chip components are mounted on thefirst mounting face opposite to the second mounting face on which theexternal substrate is mounted and a heat radiation path from the activechip components to the external substrate is not ensured, there is aproblem in that heat radiation effect is degraded.

In addition, when the active chip components are mounted on the secondmounting face, a heat radiation line through the active chip components,the second mounting face, a planar wiring pattern parallel to themounting face of the core substrate, and the external terminalelectrodes is required as the heat radiation path from the active chipcomponents to the external substrate. However, in this case, since ahigh-resistance line path only through the planar wiring pattern isincluded in the heat radiation line, in addition to low-resistance vialines along a direction vertical to the mounting face, and thermalresistance is increased on the line path, there is a problem in that theheat radiation effect is degraded.

In order to resolve the above-identified and other problems withconventional approaches, it is an object of the present disclosure toprovide a compact radio-frequency module and a compact communicationapparatus, which have improved heat radiation effect from thetransmission power amplifier.

In view of the above, a radio-frequency module according to anembodiment of the present disclosure includes a mounting substrate whichhas a first main face and a second main face, which are opposed to eachother, and in which radio-frequency components are capable of beingmounted on the first main face and the second main face; a transmissionpower amplifier (PA) that is mounted on the first main face, that is theradio-frequency component, and that has an emitter terminal; a throughelectrode that is connected to the emitter terminal of the transmissionpower amplifier and that passes through the mounting substrate betweenthe first main face and the second main face; and a ground terminal thatis connected to the through electrode.

With the above configuration, since the circuit components are mountedon both of the mounting faces of the mounting substrate, it is possibleto increase the density and reduce the size, compared with aradio-frequency module using the single-side mounted substrate. Inaddition, since the transmission power amplifier having a high heatingvalue is mounted on the first main face and the emitter terminal isconnected to the ground terminal with the through electrode formed inthe mounting substrate, a heat radiation path only through a planarwiring pattern having high thermal resistance, among the lines in themounting substrate, is capable of being excluded. Accordingly, it ispossible to provide the compact radio-frequency module having improvedheat radiation effect from the transmission power amplifier to theexternal substrate.

The radio-frequency module may be connected to an external substrate,and the ground terminal may be connected to the external substrate.

The radio-frequency module may further include first resin that isformed on the first main face and that covers at least part of thetransmission power amplifier.

With the above configuration, since the transmission power amplifierhaving high heat production is covered with the first resin, the heatradiation effect from the transmission power amplifier to the externalsubstrate is improved while improving mounting reliability of thetransmission power amplifier.

The radio-frequency module may further include a circuit componentmounted on the second main face and second resin that is formed on thesecond main face and that convers at least part of the circuitcomponent. The ground terminal may be arranged on the second resin.

With the above configuration, the through electrode is formed also inthe second resin while improving the mounting reliability of the circuitcomponent. Accordingly, it is possible to exclude the heat radiationpath only through the planar wiring pattern having high thermalresistance, among the lines formed in the mounting substrate and thesecond resin.

The radio-frequency module may further include a ground electrode layerformed of a planar wiring pattern in the mounting substrate and a firstshield electrode layer that is formed so as to cover a top face and sidefaces of the first resin and that is connected to the ground electrodelayer at side faces of the mounting substrate.

With the above configuration, it is possible to inhibit the transmissionsignal from the transmission power amplifier from being directly andexternally radiated from the radio-frequency module and it is possibleto inhibit external noise from intruding into a first electroniccomponent. In addition, since the heat generated in the transmissionpower amplifier is capable of being radiated through the first shieldelectrode layer, the heat radiation effect is improved.

The radio-frequency module may further include a second shield electrodelayer that is formed on side faces of the second resin and that isconnected to the ground electrode layer at the side faces of themounting substrate.

With the above configuration, since the second shield electrode layer isformed along with the first shield electrode layer, the entireradio-frequency module is shielded. Accordingly, it is possible tofurther inhibit the transmission signal from the transmission poweramplifier from being directly and externally radiated from theradio-frequency module and it is possible to inhibit the external noisefrom intruding into the first electronic component and a secondelectronic component. In addition, since the heat generated in thetransmission power amplifier is capable of being radiated through thesecond shield electrode layer, the heat radiation effect is furtherimproved.

In a plan view of the radio-frequency module in a direction vertical tothe first main face and the second main face, a footprint of the throughelectrode may at least partially overlap a footprint of the groundterminal.

With the above configuration, since the emitter terminal is capable ofbeing connected to the ground terminal with a substantially minimumdistance and the thermal resistance on the heat radiation path from thetransmission power amplifier to the ground terminal is capable of beingdecreased, it is possible to further improve the heat radiation effectfrom the transmission power amplifier to the external substrate. Inaddition, since the area in which the through electrode is formed in thesecond resin is capable of being limited to an area almost immediatelybelow the transmission power amplifier, it is possible to increase thearea in which the circuit component mounted on the second main face isformed. Accordingly, the degree of freedom of the arrangement of thecircuit component is improved. The circuit component may be a low noisereception amplifier.

With the above configuration, since the transmission power amplifier andthe low noise reception amplifier are arranged with the mountingsubstrate sandwiched therebetween, it is possible to ensure theisolation between the transmission power amplifier and the low noisereception amplifier to suppress interference between the transmissionsignal and the reception signal. In particular, it is possible tosuppress reduction in the reception sensitivity due to intrusion of thetransmission signal having high power into a reception path.

In a plan view of the radio-frequency module in a direction vertical tothe first main face and the second main face, the transmission poweramplifier may not overlap a footprint of the low noise receptionamplifier.

With the above configuration, since the distance between thetransmission power amplifier and the low noise reception amplifier iscapable of being further increased, and, in free space, RF energy obeysthe inverse square law where RF energy falls off with the square ofdistance, it is possible to further ensure the isolation between thetransmission power amplifier and the low noise reception amplifier tosuppress the interference between the transmission signal and thereception signal. In addition, since the through electrode with whichthe transmission power amplifier connected to the ground terminal is notrestricted by the arrangement of the low noise reception amplifier, itis possible to connect the transmission power amplifier to the groundterminal with a minimum distance.

The radio-frequency module may further include a transmission filtermounted on the first main face and a reception filter mounted on thefirst main face. In a plan view of the radio-frequency module in adirection vertical to the first main face and the second main face, afootprint of the low noise reception amplifier may at least partiallyoverlap a footprint of the reception filter.

With the above configuration, since the line length of the receptionpath including the low noise reception amplifier and the receptionfilter is capable of being decreased, it is possible to reduce thetransmission loss of the reception signal. In addition, since decreasingthe line length enables parasitic capacitance on the reception path tobe suppressed, it is possible to suppress reduction in noise figure.

The radio-frequency module may further include a transmission filtermounted on the first main face and a reception filter mounted on thefirst main face. In a plan view of the radio-frequency module in adirection vertical to the first main face, the transmission filter maybe arranged between the transmission power amplifier and the receptionfilter.

With the above configuration, since the line length of the transmissionpath including the transmission power amplifier and the transmissionfilter is capable of being decreased, it is possible to reduce thetransmission loss of the transmission signal. In addition, since theinterposition of the transmission filter enables the distance betweenthe transmission power amplifier, which outputs the transmission signalhaving high power, and the reception filter to be ensured, it ispossible to suppress the reduction in the reception sensitivity causedby the interference of the transmission signal.

In a plan view of the radio-frequency module in a direction vertical tothe first main face and the second main face, a footprint of the lownoise reception amplifier mounted on the second main face may be atleast partially overlap a footprint of the reception filter.

With the above configuration, since the line length of the transmissionpath including the transmission power amplifier and the transmissionfilter is capable of being decreased and the line length of thereception path including the low noise reception amplifier and thereception filter is capable of being decreased, it is possible to reducethe transmission loss of the reception signal and the transmissionsignal. In addition, it is possible to suppress both the reduction inthe reception sensitivity and the reduction in noise figure.

A radio-frequency module according to an embodiment of the presentdisclosure includes a mounting substrate which has a first main face anda second main face, which are opposed to each other, and in whichradio-frequency components are capable of being mounted on the firstmain face and the second main face; a transmission power amplifierarranged on the first main face; a through electrode that is connectedto the transmission power amplifier and that passes through the mountingsubstrate between the first main face and the second main face; and anexternal connection terminal that is arranged on the second main faceand that is connected to the through electrode.

With the above configuration, since the circuit components are mountedon both of the mounting faces of the mounting substrate, it is possibleto increase the density and reduce the size, compared with aradio-frequency module using the single-side mounted substrate. Inaddition, since the transmission power amplifier having a high heatingvalue is mounted on the first main face and the transmission poweramplifier is connected to the external connection terminal with thethrough electrode formed in the mounting substrate, the heat radiationpath only through the planar wiring pattern having high thermalresistance, among the lines in the mounting substrate, is capable ofbeing excluded. Accordingly, it is possible to provide the compactradio-frequency module having improved heat radiation effect from thetransmission power amplifier to the external substrate.

The radio-frequency module may be connected to an external substrate,and the external connection terminal may be connected to the externalsubstrate.

In a plan view of the radio-frequency module in a direction vertical tothe first main face and the second main face, a footprint of the throughelectrode may at least partially overlap a footprint of the externalconnection terminal.

With the above configuration, since the transmission power amplifier iscapable of being connected to the external connection terminal with asubstantially minimum distance and the thermal resistance on the heatradiation path from the transmission power amplifier is capable of beingdecreased, it is possible to further improve the heat radiation effectfrom the transmission power amplifier to the external substrate. Inaddition, since the area in which the external connection terminal isformed at the second main face side is capable of being limited to anarea almost immediately below the transmission power amplifier, it ispossible to increase the area in which the circuit component mounted onthe second main face is formed. Accordingly, the degree of freedom ofthe arrangement of the circuit component is improved.

A communication apparatus according to an embodiment of the presentdisclosure includes the external substrate and any of theradio-frequency modules described above. The external substrate has anexternal ground electrode electrically connected to the ground terminal.

With the above configuration, the transmission power amplifier having ahigh heating value is mounted on the first main face, the low noisereception amplifier is mounted on the second main face, and thetransmission power amplifier is connected to the ground terminal withthe through electrode formed in the mounting substrate. Accordingly, itis possible to provide the compact communication apparatus havingimproved heat radiation effect from the transmission power amplifier tothe external substrate.

In a plan view of the communication apparatus from a direction verticalto the first main face and the second main face, a footprint of theexternal ground electrode may at least partially overlap a footprint ofthe through electrode.

With the above configuration, the emitter terminal is capable of beingconnected to the external ground electrode with a substantially minimumdistance and the thermal resistance on the heat radiation path from thetransmission power amplifier to the external ground electrode is capableof being decreased. Accordingly, it is possible to provide thecommunication apparatus having further improved heat radiation effectfrom the transmission power amplifier to the external substrate.

According to the present disclosure, it is possible to provide a compactradio-frequency module and a compact communication apparatus, which haveimproved heat radiation effect from the transmission power amplifier.

Other features, elements, characteristics, and advantages of the presentdisclosure will become more apparent from the following detaileddescription of preferred embodiments of the present disclosure withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a first cross-sectional view (along cut IA as shown in FIGS.1B and 1C) illustrating a configuration of a radio-frequency moduleaccording to an embodiment;

FIG. 1B is a second cross-sectional view (along cut IB in FIG. 1A)illustrating the configuration of the radio-frequency module accordingto the embodiment;

FIG. 1C is a third cross-sectional view (cut along IC in FIG. 1A)illustrating the configuration of the radio-frequency module accordingto the embodiment;

FIG. 2A is a block diagram illustrating the configuration of aradio-frequency module and a communication apparatus according to anexample;

FIG. 2B is a circuit configuration diagram of an amplifier device in theradio-frequency module according to the example;

FIG. 3A is a first cross-sectional view (along cut IIIA in FIGS. 3B and3C) illustrating a configuration of the radio-frequency module accordingto the example;

FIG. 3B is a second cross-sectional view (cut along IIIB in FIG. 3B)illustrating the configuration of the radio-frequency module accordingto the example;

FIG. 3C is a third cross-sectional view (along cur IIIC in FIG. 3A)illustrating the configuration of the radio-frequency module accordingto the example;

FIG. 4A is a first cross-sectional view (along cut IVA as shown in FIGS.4B and 4C) illustrating a configuration of a radio-frequency moduleaccording to a first modification;

FIG. 4B is a second cross-sectional view (along cut IVB in FIG. 4A)illustrating the configuration of the radio-frequency module accordingto the first modification;

FIG. 4C is a third cross-sectional view (along cut IVC in FIG. 4A)illustrating the configuration of the radio-frequency module accordingto the first modification;

FIG. 5A is a first cross-sectional view (along cut VA in FIGS. 5B and5C) illustrating a configuration of a radio-frequency module accordingto a second modification;

FIG. 5B is a second cross-sectional view (along cut VB in FIG. 5A)illustrating the configuration of the radio-frequency module accordingto the second modification;

FIG. 5C is a third cross-sectional view (along cut VC in FIG. 5A)illustrating the configuration of the radio-frequency module accordingto the second modification;

FIG. 6 is a first cross-sectional view illustrating a configuration of aradio-frequency module according to a third modification; and

FIG. 7 is a first cross-sectional view illustrating a configuration of aradio-frequency module according to a fourth modification.

DETAILED DESCRIPTION

Embodiments of the present disclosure will herein be described in detailusing the embodiments with reference to the drawings. All theembodiments described below indicate comprehensive or specific examples.Numerical values, shapes, materials, components, the arrangement of thecomponents, the connection mode of the components, and so on, which areindicated in the embodiments described below, are only examples and arenot intended to limit the present disclosure. In addition, the sizes orthe ratios of the sizes of the components illustrated in the drawingsare not necessarily strictly indicated.

In this description, in A, B, and C mounted on a substrate, “arrangementof C between A and B in a plan view of the substrate (or the main faceof the substrate)” is defined as overlapping of at least part of thearea of C, which is projected in a plan view of the substrate, with aline connecting an arbitrary point in the area of A, which is projectedin a plan view of the substrate, to an arbitrary point in the area of B,which is projected in a plan view of the substrate.

Embodiments

1. Configuration of Radio-Frequency Module 1 According to Embodiment

FIG. 1A is a first cross-sectional view illustrating the configurationof a radio-frequency module 1 according to an embodiment. FIG. 1B is asecond cross-sectional view illustrating the configuration of theradio-frequency module 1 according to the embodiment. FIG. 1C is a thirdcross-sectional view illustrating the configuration of theradio-frequency module 1 according to the embodiment. More specifically,FIG. 1A is a cross-sectional view when a cross section along the IA-IAline in FIG. 1B and FIG. 1C is viewed from a Y-axis positive direction.FIG. 1B is a cross-sectional view when a cross section along the IB-IBline in FIG. 1A is viewed from a Z-axis negative direction. FIG. 1C is across-sectional view when a cross section along the IC-IC line in FIG.1A is viewed from the Z-axis negative direction.

As illustrated in FIG. 1A, the radio-frequency module 1 includes amounting substrate 30, a power amplifier (PA) 11, a low noise amplifier(LNA) 21, a transmission filter 12, a reception filter 22, resin members40A and 40B, through electrodes 51, 52, 53, and 54, and ground terminals411, 412, and 422.

The radio-frequency module 1 is capable of being electrically connectedto an external substrate 90. The external substrate 90 has groundelectrodes 911, 912, and 922 on the surface in a Z-axis positivedirection and corresponds to, for example, a mother board of a mobilephone or a communication device.

The radio-frequency module 1 is capable of being electrically connectedto the external substrate 90. The connection may be via direct mountingon the external substrate 90, or via indirect mounting on the externalsubstrate 90. Under the condition that the radio-frequency module 1 isindirectly mounted on the external substrate 90, the radio-frequencymodule 1 is mounted on another radio-frequency module mounted on theexternal substrate 90. Thus, the two or more RF modules may be gangedtogether on the external substrate 90.

An example of the circuit configuration of a radio-frequency module 1A,which is an example of the specific configuration of the radio-frequencymodule 1, will now be described.

FIG. 2A is a block diagram illustrating the configuration of theradio-frequency module 1A and a communication apparatus 8 according toan example. The radio-frequency module 1A according to the presentexample, a common input-output terminal 100, a transmission inputterminal 110, a reception output terminal 120, an antenna element 5, aradio-frequency (RF) signal processing circuit (radio-frequencyintegrated circuit (RFIC)) 6, and a baseband signal processing circuit(baseband integrated circuit (BBIC)) 7 are illustrated in FIG. 2A. Theradio-frequency module 1A illustrated in FIG. 2A is an example of thespecific circuit configuration of the radio-frequency module 1illustrated in FIG. 1A to FIG. 1C. The radio-frequency module 1A, theantenna element 5, the RFIC 6, and the BBIC 7 compose the communicationapparatus 8. The communication apparatus 8 includes the radio-frequencymodule 1 according to the present embodiment (or the radio-frequencymodule 1A according to the example) and the external substrate 90illustrated in FIG. 1A.

The radio-frequency module 1A includes the PA 11, the LNA 21,transmission filters 12A and 12B, reception filters 22A and 22B, atransmission-reception filter 32C, and switches 61, 62, 63, and 64.

The transmission filter 12A is a filter element using, for example, thetransmission band of a band (frequency band) A as a pass band. Thetransmission filter 12B is a filter element using, for example, thetransmission band of a band (frequency band) B as the pass band. Thereception filter 22A is a filter element using, for example, thereception band of the band (frequency band) A as the pass band. Thereception filter 22B is a filter element using, for example, thereception band of the band (frequency band) B as the pass band. Thetransmission filter 12A and the reception filter 22A may compose aduplexer for the band A. The transmission filter 12B and the receptionfilter 22B may compose a duplexer for the band B. Thetransmission-reception filter 32C is a filter element using, forexample, the transmission-reception band of a band (frequency band) C asthe pass band.

The switch 61 is a single pole 3 throw (SP3T) switch circuit which has acommon terminal and three selection terminals and in which the commonterminal is connected to the common input-output terminal 100 and thethree selection terminals are connected to a connection terminal betweenthe transmission filter 12A and the reception filter 22A, a connectionterminal between the transmission filter 12B and the reception filter22B, and the transmission-reception filter 32C, respectively. The switch61 has a function to switch between a band A signal path, a band Bsignal path, and a band C signal path. It is sufficient for the switch61 to be a switch circuit for conduction between the common terminal andat least one of the three selection terminals.

The arrangement of the switch 61 enables the signal of the band A, thesignal of the band B, and the signal of the band C to be transmittedwith high isolation. In addition, when the switch 61 is amulti-connection switch circuit, it is possible to concurrently transmitthe signals of at least two bands of the band A, the band B, and theband C.

The switch 62 is an SP3T switch circuit which has a common terminal andthree selection terminals and in which the common terminal is connectedto the PA 11 and the three selection terminals are connected to an inputterminal of the transmission filter 12A, an input terminal of thetransmission filter 12B, and one selection terminal of the switch 64,respectively. The switch 62 has a function to switch between a band Atransmission signal path, a band B transmission signal path, and a bandC transmission signal path. It is sufficient for the switch 62 to be aswitch circuit for conduction between the common terminal and at leastone of the three selection terminals.

The arrangement of the switch 62 enables the transmission signals of theband A, the band B, and the band C to be amplified with one PA 11.Accordingly, it is possible to reduce the radio-frequency module 1A insize.

The switch 63 is an SP3T switch circuit which has a common terminal andthree selection terminals and in which the common terminal is connectedto the LNA 21 and the three selection terminals are connected to anoutput terminal of the reception filter 22A, an output terminal of thereception filter 22B, and the other selection terminal of the switch 64,respectively. The switch 63 has a function to switch between a band Areception signal path, a band B reception signal path, and a band Creception signal path. It is sufficient for the switch 63 to be a switchcircuit for conduction between the common terminal and at least one ofthe three selection terminals.

The arrangement of the switch 63 enables the reception signals of theband A, the band B, and the band C to be amplified with one LNA 21.Accordingly, it is possible to reduce the radio-frequency module 1A insize.

The switch 64 is a single pole double throw (SPDT) switch circuit whichhas a common terminal and two selection terminals and in which thecommon terminal is connected to the transmission-reception filter 32C.The switch 64 has a function to switch a signal path including thetransmission-reception filter 32C to the transmission signal path or thereception signal path.

The arrangement of the switch 64 enables the transmission signal and thereception signal of the band C to be addressed with onetransmission-reception filter 32C. Accordingly, it is possible to reducethe radio-frequency module 1A in size.

The LNA 21 is a low noise reception amplifier including a matchingcircuit 23 and an amplifier transistor device 24. The LNA 21 amplifies aradio-frequency reception signal input from the switch 63 and suppliesthe radio-frequency reception signal to the reception output terminal120. The LNA 21 may not include the matching circuit 23.

The amplifier transistor device 24 is an amplifier device including, forexample, a bipolar transistor.

The matching circuit 23 is a circuit for matching the output impedancesfrom the reception filters 22A and 22B and the transmission-receptionfilter 32C with the input impedance into the amplifier transistor device24. The matching circuit 23 is composed of, for example, passiveelements, such as an inductor and a capacitor.

The arrangement of the matching circuit 23 enables the transmission lossand the noise figure of the reception signal to be reduced.

The PA 11 is a transmission power amplifier including a matching circuit13 and an amplifier transistor device 14. The PA 11 amplifies aradio-frequency transmission signal input from the transmission inputterminal 110. The PA 11 may not include the matching circuit 13.

The matching circuit 13 is a circuit for matching the output impedancefrom the amplifier transistor device 14 with the input impedances intothe transmission filters 12A and 12B and the transmission-receptionfilter 32C. The matching circuit 13 is composed of, for example, thepassive elements, such as an inductor and a capacitor.

The arrangement of the matching circuit 13 enables the transmission lossof the transmission signal to be reduced.

The configuration of the PA 11 will now be described in detail,illustrating the circuit configuration of the PA 11 as an example.

FIG. 2B is a circuit configuration diagram of the amplifier transistordevice 14 in the radio-frequency module 1A according to the example. Asillustrated in FIG. 2B, the amplifier transistor device 14 includes atransistor 140, capacitors 141 and 142, a bias circuit 143, a collectorterminal 144, an emitter terminal 111, an input terminal 145, and anoutput terminal 146.

The transistor 140 is, for example, a bipolar transistor of anemitter-grounded type, which has a collector, an emitter, and a base.The transistor 140 amplifies radio-frequency current input into the baseand outputs the radio-frequency current from the collector. Thetransistor 140 may be a field effect transistor having a drain, asource, and a gate. In this case, the transistor 140 is, for example,the field effect transistor of a source grounded type, which amplifiesthe radio-frequency current input into the gate and outputs theradio-frequency current from the drain.

The capacitor 141 is a direct-current (DC) cut capacitor element and hasa function to prevent leakage of direct current into the input terminal145 with direct-current bias voltage applied from the bias circuit 143to the base.

The capacitor 142 is a DC cut capacitor element and has a function toremove a direct-current component of a radio-frequency amplificationsignal on which the direct-current bias voltage is superimposed. Theradio-frequency amplification signal from which the direct-currentcomponent is removed is output from the output terminal 146.

The bias circuit 143 is connected to the base of the transistor 140 andhas a function to optimize the operating point of the transistor 140 byapplying bias voltage to the base.

In the above circuit configuration of the amplifier transistor device14, a radio-frequency signal RFin input from the input terminal 145flows from the base of the transistor 140 to the emitter thereof as basecurrent Ib. The base current Ib is amplified by the transistor 140 andflows as collector current Ic. A radio-frequency signal RFoutcorresponding to the collector current Ic is output from the outputterminal 146. At this time, high current resulting from combination ofthe base current Ib with the collector current Ic flows from the emitterterminal 111 to ground.

The emitter terminal 111 may be arranged outside the amplifiertransistor device 14 and inside the PA 11. In other words, the emitterterminal 111 may not be included in the amplifier transistor device 14and may be included in the PA 11.

Referring back to FIG. 2A, the configuration of the communicationapparatus 8 will be described.

The RFIC 6 performs signal processing, such as down-conversion, on theradio-frequency reception signal input from the antenna element 5through the radio-frequency module 1A and supplies a reception signalresulting from the signal processing to the BBIC 7.

The BBIC 7 is a circuit that performs signal processing using anintermediate frequency band lower than the frequency of theradio-frequency signal in a front end unit. The signal processed in theBBIC 7 is used as, for example, an image signal for image display or anaudio signal for talking with a speaker.

With the above configuration, the radio-frequency module 1A is capableof selecting any of the band A radio-frequency signal, the band Bradio-frequency signal, and the band C radio-frequency signal through aswitching operation of the switches 61 to 64 and transmitting theselected radio-frequency signal. Although the radio-frequency module 1Ais applied to a (non-carrier aggregation (CA)) mode in which each of thetransmission-reception signals of the above three frequency bands isindependently transmitted, the radio-frequency module 1A may be appliedto a (CA) mode in which two or more transmission-reception signals,among the transmission-reception signals of the above three frequencybands, are concurrently transmitted.

Although the radio-frequency module 1A, which is atransmission-reception demultiplexing-multiplexing circuit, isexemplified as the radio-frequency module in the present embodiment, theradio-frequency module according to the embodiments of the presentdisclosure may be a transmission multiplexing circuit and the number offrequency bands (signal paths) is not limited.

In addition to the components in the circuit illustrated in FIG. 2A,electronic components, such as a capacitor, an inductor, and aresistance element, may be arranged at nodes with which the respectivecircuit elements are connected.

Referring back to FIG. 1A, the configuration of the radio-frequencymodule 1 will be described.

The mounting substrate 30 is a dual-side mounted substrate which has amain face 30 a and a main face 30 b, which are opposed to each other,and in which circuit components are mounted on each of the main faces 30a and 30 b. The main face 30 a is a first main face of the mountingsubstrate 30 at the Z-axis positive direction side and the main face 30b is a second main face of the mounting substrate 30 at the Z-axisnegative direction side. The mounting substrate 30 is a multilayersubstrate in which multiple layers are laminated. The mounting substrate30 is, for example, a ceramic multilayer substrate or a printed circuitboard (PCB) substrate. The mounting substrate 30 has a planar wiringpattern set to ground potential.

The PA 11 is a transmission power amplifier that has the emitterterminal 111 and an emitter terminal 112, that is mounted on the mainface 30 a, and that amplifies the radio-frequency transmission signal.The PA 11 has a base terminal (not illustrated in FIG. 1A), thecollector terminal 144 (not illustrated in FIG. 1A), the emitterterminals 111 and 112, and the amplifier transistor device (notillustrated in FIG. 1A). The amplifier transistor device 14 may have aconfiguration in which multiple transistors 140 are cascade-connected.In this case, the amplifier transistor device 14 may have multiple baseterminals, multiple collector terminals, and multiple emitter terminals.From this point of view, the multiple emitter terminals 111 and 112 areillustrated in FIG. 1A.

The base terminal (not illustrated in FIG. 1A and corresponding to theinput terminal 145 in FIG. 2B), the collector terminal 144 (notillustrated in FIG. 1A and illustrated in FIG. 2B), and the emitterterminals 111 and 112 (illustrated in FIG. 1A) are arranged on the mainface 30 a and are formed of metal electrode layers, metal bump members,or the likes.

In the amplifier transistor device 14, the base of the transistor 140 isconnected to the above base terminal, the collector of the transistor140 is connected to the collector terminal 144, the emitter of thetransistor 140 is connected to the emitter terminal 111 or 112, and thecollector current Ic flows from the collector terminal 144 to theemitter terminal 111 or 112, as described above with reference to FIG.2B. When the amplifier transistor device 14 is the field effecttransistor, the gate of the transistor 140 is connected to the inputterminal 145, the drain of the transistor 140 is connected to a drainterminal (corresponding to the collector terminal 144), the source ofthe transistor 140 is connected to a source terminal (corresponding tothe emitter terminal 111 or 112), and drain current flows from the drainterminal to the source terminal.

The LNA 21 is a circuit component that has connection terminals 211 and212 connected to the mounting substrate 30 and that is mounted on themain face 30 b. The LNA 21 is, for example, a low noise receptionamplifier that amplifies the radio-frequency reception signal. Althoughthe LNA 21 is exemplified as the circuit component in the presentembodiment, the circuit component may be an active element or a passiveelement other than the low noise reception amplifier.

The transmission filter 12 is a filter element that has connectionterminals 121 and 122 connected to the mounting substrate 30 and thatuses the transmission band of a certain frequency band as the pass band.

The reception filter 22 is a filter element that has connectionterminals 221 and 222 connected to the mounting substrate 30 and thatuses the reception band of a certain frequency band as the pass band.The connection terminal 211 of the LNA 21 is connected to the connectionterminal 221 of the reception filter 22 with the through electrode 53.

With the above configuration, since the line connecting the receptionfilter 22 to the LNA 21 is capable of being shortened, it is possible toreduce the transmission loss of the reception signal.

The ground terminals 411, 412, and 422 are arranged at the main face 30b side with respect to the mounting substrate 30, and thus serve asground nodes. The ground terminal 411 is electrically connected to theemitter terminal 111 of the PA 11 with the through electrode 51 and isdirectly connected to the ground electrode 911 of the external substrate90. The ground terminal 412 is electrically connected to the emitterterminal 112 of the PA 11 with the through electrode 52 and is directlyconnected to the ground electrode 912 of the external substrate 90. Theground terminal 422 is electrically connected to the connection terminal222 of the reception filter 22 with the through electrode 54 and isdirectly connected to the ground electrode 922 of the external substrate90. The ground terminals 411, 412, and 422 are joined to the groundelectrodes 911, 912, and 922, respectively, with, for example, soldermembers interposed therebetween. The ground terminals 411, 412, and 422may be bump members (including solder balls) joined to the leading endsin the Z-axis negative direction of the through electrodes 51, 52, and54, respectively. In addition, the ground terminals 411, 412, and 422may be plating layers or the likes formed on the leading ends in theZ-axis negative direction of the through electrodes 51, 52, and 54,respectively. Furthermore, when the electrode layers and electrodeterminals are not formed on the leading ends in the Z-axis negativedirection of the through electrodes 51, 52, and 54 as theradio-frequency module 1, the ground terminals 411, 412, and 422 aredefined as the leading ends themselves in the Z-axis negative directionof the through electrodes 51, 52, and 54, respectively. In other words,the leading ends in the Z-axis negative direction of the throughelectrodes 51, 52, and 54 are joined to the ground electrodes 911, 912,and 922, respectively, with the solder members or the likes.

The through electrode 51 is an electrode with which the emitter terminal111 is electrically connected to the ground terminal 411 and whichpasses through the mounting substrate 30 from the main face 30 a to themain face 30 b. The through electrode 52 is an electrode with which theemitter terminal 112 is electrically connected to the ground terminal412 and which passes through the mounting substrate 30 from the mainface 30 a to the main face 30 b.

The through electrode 53 is an electrode with which the connectionterminal 221 of the reception filter 22 is electrically connected to theconnection terminal 211 of the LNA 21 and which passes through themounting substrate 30 from the main face 30 a to the main face 30 b. Thethrough electrode 54 is an electrode with which the connection terminal222 of the reception filter 22 is electrically connected to the groundterminal 422 and which passes through the mounting substrate 30 from themain face 30 a to the main face 30 b.

In the present embodiment, the through electrodes 51, 52, and 54 passthrough not only the mounting substrate 30 but also the resin member40B.

The resin member 40A is first resin that is formed on the main face 30 aand that covers the side faces and the top faces of the PA 11, thetransmission filter 12, and the reception filter 22. It is sufficientfor the resin member 40A to cover at least the side faces of the PA 11.

The resin member 40B is second resin that is formed on the main face 30b and that covers the side faces and the top face of the LNA 21. It issufficient for the resin member 40B to cover at least the side faces ofthe circuit component.

The through electrodes 53 and 54 and the resin members 40A and 40B arenot essential components for the radio-frequency module 1 according tothe present embodiment.

As discussed above, a radio-frequency module using a single-side mountedsubstrate is exemplified as a radio-frequency module in the related art.According to this conventional approach, because the circuit componentsare arranged on a same plane, a conventional approach to reducing sizeand enhancing integration has been addressed by decreasing the spacingsbetween the circuit components and reducing the sizes of the circuitcomponents themselves. However, under the use case of long termevolution (LTE) communication and 5th generation (5G) mobilecommunication systems, the area in which the radio-frequency componentsare capable of being installed on a mobile terminal is further decreasedin size so there is a practical limit on the reduction in the size of aplanar product. In addition, since the PA and the LNA are arranged onthe same plane in the single-side mounting method, the LNA issusceptible to RFI due to the co-planar geometry with the PA, and it isdifficult to reliably ensure isolation between transmission andreception circuitry. Moreover, the LNA is particularly susceptible toRFI from the co-located PA because the LNA amplifies relatively weaksignals, and thus any extraneous emissions from the PA may find anunintended propagation path into the LNA signal path, thereby having theundesirable effect of raising the effective noise/interference floor ofthe LNA.

In contrast, with the above configuration of the radio-frequency module1 according to the present embodiment, since the radio-frequency circuitcomponents are mounted on both of the main faces 30 a and 30 b of themounting substrate 30, it is possible to increase the density and reducethe size, compared with the radio-frequency module using the single-sidemounted substrate.

In addition, the PA 11 having a high heating value is mounted on themain face 30 a, the through electrode 51 formed in the mountingsubstrate 30 is connected to the emitter terminal 111 and the groundterminal 411, and the through electrode 52 formed in the mountingsubstrate 30 is connected to the emitter terminal 112 and the groundterminal 412. With this configuration, among the lines in the mountingsubstrate 30, a heat radiation path only through the planar wiringpattern along an XY plane direction having high thermal resistance iscapable of being excluded. Accordingly, it is possible to provide thecompact radio-frequency module 1 having improved heat radiation effectfrom the PA 11 to the external substrate 90.

Specifically, in the radio-frequency module 1 according to the presentembodiment, the PA 11 is arranged at a side opposite to the side wherethe ground terminals 411 and 412 are formed with respect to the mountingsubstrate 30. In addition, the ground terminals 411 and 412 are arrangedat the main face 30 b side, among the main face 30 a and the main face30 b, with respect to the mounting substrate 30. The heat radiation pathof the PA 11 is the emitter terminal 111-the through electrode 51-theground terminal 411 and the emitter terminal 112-the through electrode52-the ground terminal 412. If the PA 11 is arranged at the side wherethe ground terminals 411 and 412 are formed with respect to the mountingsubstrate 30, the emitter terminals 111 and 112 of the PA 11 areconnected to the main face 30 b and are connected to the groundterminals 411 and 412, respectively, with the through electrodes in theresin member 40B via the planar wiring pattern extending in the XY planedirection of the mounting substrate 30. In contrast, when the PA 11 isarranged on the main face 30 a, as in the present embodiment, the heatradiation path is composed of a path through the through electrodes 51and 52 and does not include the path only through the planar wiringpattern in the mounting substrate 30. In other words, since the emitterterminals 111 and 112 of the PA 11 are connected to the ground terminals411 and 412 with the through electrodes 51 and 52, respectively, theheat radiation path having low thermal resistance is capable of beingrealized to improve the heat radiation effect of the radio-frequencymodule 1.

Since the arrangement of the resin member 40A causes the PA 11 havinghigh heat production to be covered with the resin member 40A, the heatradiation effect from the PA 11 to the external substrate 90 is improvedwhile improving mounting reliability of the PA 11.

In addition, in the present embodiment, the ground terminals 411, 412,and 422 are arranged on the resin member 40B, among the resin members40A and 40B. In particular, the ground terminals 411, 412, and 422 arearranged on the surface (in the Z-axis negative direction) of the resinmember 40B (the main face that is not in contact with the main face 30b, among the two main faces opposed to each other) in the presentembodiment.

With the above configuration, the arrangement of the resin members 40Aand 40B causes the through electrodes 51, 52, and 54 to be formed alsoin the resin member 40B while improving the mounting reliability of thePA 11 and the LNA 21. Accordingly, it is possible to exclude the heatradiation path only through the planar wiring pattern having highthermal resistance, among the lines formed in the mounting substrate 30and the resin member 40B, across the mounting substrate 30 and the resinmember 40B.

As illustrated in FIG. 1C, in a plan view of the radio-frequency module1 from a direction vertical to the main faces 30 a and 30 b (from theZ-axis direction), a footprint of the through electrode 51 may overlapwith a footprint of the ground terminal 411 and a footprint of thethrough electrode 52 may overlap with a footprint the ground terminal412.

With the above configuration, the emitter terminal 111 is capable ofbeing connected to the ground terminal 411 with a substantially minimumdistance and the emitter terminal 112 is capable of being connected tothe ground terminal 412 with a substantially minimum distance.Accordingly, since the thermal resistance on the heat radiation pathfrom the PA 11 to the ground terminals 411 and 412 is capable of beingdecreased, it is possible to further improve the heat radiation effectfrom the PA 11 to the external substrate 90. In addition, since the areain which the through electrodes 51 and 52 are formed in the resin member40B is capable of being limited to an area almost immediately below thePA 11, it is possible to increase the area in which the circuitcomponents mounted on the main face 30 b are formed. Accordingly, thedegree of freedom of the arrangement of the circuit components isimproved.

A footprint of the through electrode 51 may not completely overlap witha footprint of the ground terminal 411, as in FIG. 1C, and it issufficient for at least part of the footprint of the through electrode51 to overlap with a footprint of the ground terminal 411. In addition,it is sufficient for at least part of the footprint of the throughelectrode 52 to overlap with a footprint of the ground terminal 412.

In the above plan view, the footprint of the through electrode 51desirably overlaps with the footprint of the ground electrode 911 andthe footprint of the through electrode 52 desirably overlaps with the afootprint of ground electrode 912.

With the above configuration, the emitter terminal 111 is capable ofbeing connected to the ground electrode 911 with a substantially minimumdistance and the emitter terminal 112 is capable of being connected tothe ground electrode 912 with a substantially minimum distance.Accordingly, since the thermal resistance on the heat radiation pathfrom the PA 11 to the external substrate 90 is capable of beingdecreased, it is possible to provide the communication apparatus 8having the improved heat radiation effect from the PA 11 to the externalsubstrate 90. The footprint of the through electrode 51 may notcompletely overlap with the footprint of the ground electrode 911 and itis sufficient for at least part of the footprint of the throughelectrode 51 to overlap with the footprint of the ground electrode 911.In addition, it is sufficient for at least part of the footprint of thethrough electrode 52 to overlap with the footprint of the groundelectrode 912.

Since the PA 11 and the LNA 21 are arranged with the mounting substrate30 sandwiched therebetween in the present embodiment, it is possible toensure the isolation between the PA 11 and the LNA 21 to suppressinterference between the transmission signal and the reception signal.In particular, it is possible to suppress reduction in the receptionsensitivity due to intrusion of the transmission signal having highpower into a reception path.

When the matching circuit 13 in the PA 11 includes a first chip inductorand the matching circuit 23 in the LNA 21 includes a second chipinductor in the present example, the first inductor is desirably mountedon the main face 30 a and the second inductor is desirably mounted onthe main face 30 b. With this configuration, since the first inductorarranged on a transmission system circuit and the second inductorarranged on a reception system circuit are arranged with the mountingsubstrate 30 interposed therebetween, the magnetic-field couplingbetween the first inductor and the second inductor is capable of beingsuppressed. Accordingly, it is possible to ensure the isolation betweenthe transmission system circuit and the reception system circuit tosuppress the interference between the transmission signal and thereception signal. In particular, it is possible to suppress thereduction in the reception sensitivity due to intrusion of thetransmission signal having high power into the reception path.

In the radio-frequency module 1A illustrated in FIG. 2A, a third chipinductor for impedance matching may be arranged between the switch 61and the transmission filter 12A and the reception filter 22A, and afourth chip inductor for impedance matching may be arranged between theswitch 61 and the transmission filter 12B and the reception filter 22B.In addition, a fifth chip inductor for impedance matching may bearranged between the common input-output terminal 100 and the switch 61.

In the above configuration, the first inductor is desirably mounted onthe main face 30 a and the third inductor is desirably mounted on themain face 30 b. With this configuration, since the first inductor andthe third inductor are arranged with the mounting substrate 30sandwiched therebetween, it is possible to suppress the magnetic-fieldcoupling between the first inductor and the third inductor. Accordingly,since the intrusion of the transmission signal into the reception systemcircuit not through the transmission filter 12A is capable of beingsuppressed, it is possible to ensure the isolation between thetransmission system circuit and the reception system circuit to suppressthe interference between the transmission signal and the receptionsignal. In particular, it is possible to suppress the reduction in thereception sensitivity due to intrusion of the transmission signal havinghigh power into the reception path.

In addition, in the above configuration, the first inductor is desirablymounted on the main face 30 a and the fourth inductor is desirablymounted on the main face 30 b. With this configuration, since the firstinductor and the fourth inductor are arranged with the mountingsubstrate 30 sandwiched therebetween, it is possible to suppress themagnetic-field coupling between the first inductor and the fourthinductor. Accordingly, since the intrusion of the transmission signalinto the reception system circuit not through the transmission filter12B is capable of being suppressed, it is possible to ensure theisolation between the transmission system circuit and the receptionsystem circuit to suppress the interference between the transmissionsignal and the reception signal. In particular, it is possible tosuppress the reduction in the reception sensitivity due to intrusion ofthe transmission signal having high power into the reception path.

Furthermore, in the above configuration, the first inductor is desirablymounted on the main face 30 a and the fifth inductor is desirablymounted on the main face 30 b. With this configuration, since the firstinductor and the fifth inductor are arranged with the mounting substrate30 sandwiched therebetween, it is possible to suppress themagnetic-field coupling between the first inductor and the fifthinductor. Accordingly, since the intrusion of the transmission signalinto the reception system circuit not through the transmission filters12A and 12B is capable of being suppressed, it is possible to ensure theisolation between the transmission system circuit and the receptionsystem circuit to suppress the interference between the transmissionsignal and the reception signal. In particular, it is possible tosuppress the reduction in the reception sensitivity due to intrusion ofthe transmission signal having high power into the reception path.

Furthermore, in the above configuration, the third inductor is desirablymounted on the main face 30 a and the second inductor is desirablymounted on the main face 30 b. With this configuration, since the thirdinductor and the second inductor are arranged with the mountingsubstrate 30 sandwiched therebetween, it is possible to suppress themagnetic-field coupling between the third inductor and the secondinductor. Accordingly, since the intrusion of the transmission signalinto the reception system circuit not through the reception filter 22Ais capable of being suppressed, it is possible to ensure the isolationbetween the transmission system circuit and the reception system circuitto suppress the interference between the transmission signal and thereception signal. In particular, it is possible to suppress thereduction in the reception sensitivity due to intrusion of thetransmission signal having high power into the reception path.

Furthermore, in the above configuration, the fourth inductor isdesirably mounted on the main face 30 a and the second inductor isdesirably mounted on the main face 30 b. With this configuration, sincethe fourth inductor and the second inductor are arranged with themounting substrate 30 sandwiched therebetween, it is possible tosuppress the magnetic-field coupling between the fourth inductor and thesecond inductor. Accordingly, since the intrusion of the transmissionsignal into the reception system circuit not through the receptionfilter 22B is capable of being suppressed, it is possible to ensure theisolation between the transmission system circuit and the receptionsystem circuit to suppress the interference between the transmissionsignal and the reception signal. In particular, it is possible tosuppress the reduction in the reception sensitivity due to intrusion ofthe transmission signal having high power into the reception path.

Furthermore, in the above configuration, the fifth inductor is desirablymounted on the main face 30 a and the second inductor is desirablymounted on the main face 30 b. With this configuration, since the fifthinductor and the second inductor are arranged with the mountingsubstrate 30 sandwiched therebetween, it is possible to suppress themagnetic-field coupling between the fifth inductor and the secondinductor. Accordingly, since the intrusion of the transmission signalinto the reception system circuit not through the reception filters 22Aand 22B is capable of being suppressed, it is possible to ensure theisolation between the transmission system circuit and the receptionsystem circuit to suppress the interference between the transmissionsignal and the reception signal. In particular, it is possible tosuppress the reduction in the reception sensitivity due to intrusion ofthe transmission signal having high power into the reception path.

2. Configuration of Radio-Frequency Module 1A According to Example

FIG. 3A is a first cross-sectional view illustrating the configurationof the radio-frequency module 1A according to a first example. FIG. 3Bis a second cross-sectional view illustrating the configuration of theradio-frequency module 1A according to the first example. FIG. 3C is athird cross-sectional view illustrating the configuration of theradio-frequency module 1A according to the first example. Morespecifically, FIG. 3A is a cross-sectional view when a cross sectionalong the IIIA-IIIA line in FIG. 3B and FIG. 3C is viewed from theY-axis positive direction. FIG. 3B is a cross-sectional view when across section along the IIIB-IIIB line in FIG. 3A is viewed from theZ-axis negative direction. FIG. 3C is a cross-sectional view when across section along the IIIC-IIIC line (a main face 40 b) in FIG. 3A isviewed from the Z-axis negative direction. Not only the circuit elementsand the terminals (solid lines) arranged on the respective crosssections but also the circuit elements (broken lines) that exist in aperspective view from the Z-axis direction are illustrated in FIG. 3Band FIG. 3C.

As illustrated in FIG. 3A to FIG. 3C, the radio-frequency module 1Aincludes the PA 11, the LNA 21, the transmission filters 12A and 12B,the reception filters 22A and 22B, the transmission-reception filter32C, and the switches 61 to 64. The radio-frequency module 1A accordingto the present example is an example of the specific configuration ofthe radio-frequency module 1 according to the first embodiment. Theradio-frequency module 1A according to the present example differs fromthe radio-frequency module 1 according to the embodiment in that theconfigurations of the filters and the switches are added in detail. Theradio-frequency module 1A according to the present example will bedescribed, focusing on the points different from the radio-frequencymodule 1 according to the embodiment.

The PA 11, the LNA 21, the transmission filters 12A and 12B, thereception filters 22A and 22B, the transmission-reception filter 32C,and the switches 61 to 64 are connected in the same manner as in thecircuit configuration illustrated in FIG. 2A.

With the configuration of the radio-frequency module 1A according to thefirst example, since the circuit components are mounted on both of themain faces 30 a and 30 b of the mounting substrate 30, as illustrated inFIG. 3A, it is possible to increase the density and reduce the size,compared with the radio-frequency module using the single-side mountedsubstrate. In addition, the PA 11 having a high heating value is mountedon the main face 30 a, the through electrode 51 formed in the mountingsubstrate 30 is connected to the emitter terminal 111 and the groundterminal 411, and the through electrode 52 is connected to the emitterterminal 112 and the ground terminal 412. With this configuration, amongthe lines in the mounting substrate 30, the heat radiation path onlythrough the planar wiring pattern along the XY plane direction havinghigh thermal resistance is capable of being excluded. Accordingly, it ispossible to provide the compact radio-frequency module 1A having theimproved heat radiation effect from the PA 11 to the external substrate90.

As illustrated in FIG. 3C, in a plan view of the radio-frequency module1A from the direction vertical to the main faces 30 a and 30 b (from theZ-axis direction), a footprint of the through electrode 51 overlaps witha footprint of the ground terminal 411 and a footprint of the throughelectrode 52 overlaps with a footprint of the ground terminal 412.Accordingly, since the thermal resistance on the heat radiation pathfrom the PA 11 to the ground terminals 411 and 412 is capable of beingdecreased, it is possible to further improve the heat radiation effectfrom the PA 11 to the external substrate 90. In addition, since the areain which the through electrodes 51 and 52 are formed in the resin member40B is capable of being limited to an area almost immediately below thePA 11, it is possible to increase the area in which the circuitcomponents mounted on the main face 30 b are formed. Accordingly, thedegree of freedom of the arrangement of the circuit components isimproved.

As illustrated in FIG. 3A to FIG. 3C, in a plan view of theradio-frequency module 1A from the direction vertical to the main faces30 a and 30 b, a foot a footprint of the PA 11 desirably does notoverlap with a footprint of the LNA 21.

With the above configuration, since the distance between the PA 11 andthe LNA 21 is capable of being further increased and the electromagneticfield coupling between the PA 11 and the LNA 21 is capable of beingsuppressed, in addition to the arrangement of the PA 11 and the LNA 21on the main faces 30 a and 30 b, respectively, it is possible to furtherensure the isolation between the PA 11 and the LNA 21. In addition,since the through electrodes 51 and 52 with which the PA 11 is connectedto the ground terminals 411 and 412, respectively, are not restricted bythe arrangement of the LNA 21, it is possible to connect the PA 11 tothe ground terminals 411 and 412 with a minimum distance.

In the above plan view, it is desirable that a footprint of the LNA 21at least partially overlaps with a footprint of the reception filters22A and 22B, as illustrated in FIG. 3A and FIG. 3B.

With the above configuration, since the line length of the receptionpath including the LNA 21 and the reception filter 22A or 22B is capableof being decreased, it is possible to reduce the transmission loss ofthe reception signal. In addition, since decreasing the line lengthenables parasitic capacitance on the reception path to be suppressed, itis possible to suppress reduction in the noise figure of the LNA 21.

In the above plan view, the transmission filters 12A and 12B aredesirably arranged between the PA 11 and the reception filters 22A and22B, as illustrated in FIG. 3A and FIG. 3B.

With the above configuration, since the line length of the transmissionpath including the PA 11 and the transmission filters 12A and 12B iscapable of being decreased, it is possible to reduce the transmissionloss of the transmission signal. In addition, since the interposition ofthe transmission filters 12A and 12B enables the distance between the PA11, which outputs the transmission signal having high power, and thereception filters 22A and 22B to be ensured, it is possible to suppressthe reduction in the reception sensitivity caused by the interference ofthe transmission signal.

3. Configuration of Radio-Frequency Module 2 According to FirstModification

FIG. 4A is a first cross-sectional view illustrating the configurationof a radio-frequency module 2 according to a first modification. FIG. 4Bis a second cross-sectional view illustrating the configuration of theradio-frequency module 2 according to the first modification. FIG. 4C isa third cross-sectional view illustrating the configuration of theradio-frequency module 2 according to the first modification. Morespecifically, FIG. 4A is a cross-sectional view when a cross sectionalong the IVA-IVA line in FIG. 4B and FIG. 4C is viewed from the Y-axispositive direction. FIG. 4B is a cross-sectional view when a crosssection along the IVB-IVB line in FIG. 4A is viewed from the Z-axisnegative direction. FIG. 4C is a cross-sectional view when a crosssection along the IVC-IVC line in FIG. 4A is viewed from the Z-axisnegative direction.

As illustrated in FIG. 4A, the radio-frequency module 2 includes themounting substrate 30, the PA 11, the LNA 21, the transmission filter12, the reception filter 22, the resin members 40A and 40B, the throughelectrodes 51, 52, 53, and 54, the ground terminals 411, 412, and 422, aground electrode layer 30G, and a shield electrode layer 40G. Theradio-frequency module 2 according to the present modification differsfrom the radio-frequency module 1 according to the embodiment as theconfiguration in that the ground electrode layer 30G and the shieldelectrode layer 40G are arranged. A description of the same points ofthe radio-frequency module 2 according to the present modification as inthe radio-frequency module 1 according to the embodiment is omitted andthe radio-frequency module 2 according to the present modification willbe described, focusing on the points different from the radio-frequencymodule 1 according to the embodiment.

The ground electrode layer 30G is an electrode layer that is formed ofthe planar wiring pattern in the mounting substrate 30 and that is setto the ground potential.

The shield electrode layer 40G is a first shield electrode layer that isformed so as to cover the top face and the side faces of the resinmember 40A and that is connected to the ground electrode layer 30G atthe side faces of the mounting substrate 30.

With the above configuration, it is possible to inhibit the transmissionsignal from the PA 11 from being directly and externally radiated fromthe radio-frequency module 2 and it is possible to inhibit externalnoise from intruding into the circuit components on the main face 30 a.In addition, since the heat generated in the PA 11 is capable of beingradiated through the shield electrode layer 40G, the heat radiationeffect is improved.

4. Configuration of Radio-Frequency Module 3 According to SecondModification

FIG. 5A is a first cross-sectional view illustrating the configurationof a radio-frequency module 3 according to a second modification. FIG.5B is a second cross-sectional view illustrating the configuration ofthe radio-frequency module 3 according to the second modification. FIG.5C is a third cross-sectional view illustrating the configuration of theradio-frequency module 3 according to the second modification. Morespecifically, FIG. 5A is a cross-sectional view when a cross sectionalong the VA-VA line in FIG. 5B and FIG. 5C is viewed from the Y-axispositive direction. FIG. 5B is a cross-sectional view when a crosssection along the VB-VB line in FIG. 5A is viewed from the Z-axisnegative direction. FIG. 5C is a cross-sectional view when a crosssection along the VC-VC line in FIG. 5A is viewed from the Z-axisnegative direction.

As illustrated in FIG. 5A, the radio-frequency module 3 includes themounting substrate 30, the PA 11, the LNA 21, the transmission filter12, the reception filter 22, the resin members 40A and 40B, the throughelectrodes 51, 52, 53, and 54, the ground terminals 411, 412, and 422,the ground electrode layer 30G, the shield electrode layer 40G, andsubstantially column-shaped shield electrodes 41G. The radio-frequencymodule 3 according to the present modification differs from theradio-frequency module 2 according to the first modification as theconfiguration in that the substantially column-shaped shield electrodes41G are arranged. A description of the same points of theradio-frequency module 3 according to the present modification as in theradio-frequency module 2 according to the first modification is omittedand the radio-frequency module 3 according to the present modificationwill be described, focusing on the points different from theradio-frequency module 2 according to the first modification.

The substantially column-shaped shield electrodes 41G are a secondshield electrode layer that is formed on the side faces of the resinmember 40B and that is connected to the ground electrode layer 30G atthe side faces of the mounting substrate 30. As illustrated in FIG. 5C,the substantially column-shaped shield electrodes 41G are substantiallysemi-columnar column-shaped electrodes resulting from cutting in theZ-axis direction of substantially columnar via electrodes passingthrough the mounting substrate 30 and the resin member 40B in the Z-axisdirection. Multiple substantially column-shaped shield electrodes 41Gare arranged at the side faces of the resin member 40B.

With the above configuration, since the substantially column-shapedshield electrodes 41G are formed along with the shield electrode layer40G, the entire radio-frequency module 3 is shielded. Accordingly, it ispossible to further inhibit the transmission signal from the PA 11 frombeing directly and externally radiated from the radio-frequency module 3and it is possible to inhibit the external noise from intruding into thecircuit components on the main faces 30 a and 30 b. In addition, sincethe heat generated in the PA 11 is capable of being radiated through thesubstantially column-shaped shield electrodes 41G, the heat radiationeffect is further improved.

The substantially column-shaped shield electrodes 41G may be a layerelectrode formed so as to cover the side faces of the resin member 40B,like the shield electrode layer 40G.

5. Configuration of Radio-Frequency Module 4A According to ThirdModification

FIG. 6 is a first cross-sectional view illustrating the configuration ofa radio-frequency module 4A according to a third modification. Asillustrated in FIG. 6, the radio-frequency module 4A includes themounting substrate 30, the PA 11, the LNA 21, the transmission filter12, the reception filter 22, the resin members 40A and 40B, throughelectrodes 51A and 52A, the through electrodes 53 and 54, groundterminals 411A and 412A, and the ground terminal 422. Theradio-frequency module 4A according to the present modification differsfrom the radio-frequency module 1 according to the embodiment in theshapes of the through electrodes 51A and 52A. A description of the samepoints of the radio-frequency module 4A according to the presentmodification as in the radio-frequency module 1 according to theembodiment is omitted and the radio-frequency module 4A according to thepresent modification will be described, focusing on the points differentfrom the radio-frequency module 1 according to the embodiment.

The through electrode 51A is an electrode that electrically connects theemitter terminal 111 to the ground terminal 411A and that passes throughthe mounting substrate 30 from the main face 30 a to the main face 30 b.The through electrode 52A is an electrode that electrically connects theemitter terminal 112 to the ground terminal 412A and that passes throughthe mounting substrate 30 from the main face 30 a to the main face 30 b.

Here, the through electrode 51A is not composed of one substantiallycylindrical via electrode extending from the main face 30 a to the mainface 30 b in the mounting substrate 30 and has a structure in whichmultiple substantially cylindrical via electrodes are connected inseries to each other. The planar wiring patterns along the respectivelayers are formed between the multiple substantially cylindrical viaelectrodes connected in series to each other and the substantiallycylindrical via electrodes adjacent to each other in the Z-axisdirection are at least partially overlapped with each other in a planview of the main face 30 b from the main face 30 a. In other words, nopath in the XY plane direction only through the planar wiring patternexists in the through electrode 51A and the path in the Z-axis directionexists in the through electrode 51A. The through electrode 52A has thesame structure as that of the through electrode 51A.

With the above configuration, the emitter terminal 111 is not limitedlyoverlapped with the ground terminal 411A in the above plan view due tothe through electrode 51A and it is possible to increase the degree offreedom of the arrangement of the ground terminal 411A. In addition, theemitter terminal 112 is not limitedly overlapped with the groundterminal 412A in the above plan view due to the through electrode 52Aand it is possible to increase the degree of freedom of the arrangementof the ground terminal 412A. Furthermore, for example, the size(diameter) of the multiple substantially cylindrical via electrodes maybe changed and multiple substantially cylindrical via electrodes may beprovided in the same layer to enable further decrease of the thermalresistance on the heat radiation path.

6. Configuration of Radio-Frequency Module 4B According to FourthModification

FIG. 7 is a first cross-sectional view illustrating the configuration ofa radio-frequency module 4B according to a fourth modification. Asillustrated in FIG. 7, the radio-frequency module 4B includes themounting substrate 30, the PA 11, the LNA 21, the transmission filter12, the reception filter 22, the resin members 40A and 40B, throughelectrodes 51B and 52B, the through electrodes 53 and 54, groundterminals 411B and 412B, and the ground terminal 422. Theradio-frequency module 4B according to the present modification differsfrom the radio-frequency module 1 according to the embodiment in theshapes of the through electrodes 51B and 52B. A description of the samepoints of the radio-frequency module 4B according to the presentmodification as in the radio-frequency module 1 according to theembodiment is omitted and the radio-frequency module 4B according to thepresent modification will be described, focusing on the points differentfrom the radio-frequency module 1 according to the embodiment.

The through electrode 51B is an electrode that electrically connects theemitter terminal 111 to the ground terminal 411B and that passes throughthe mounting substrate 30 from the main face 30 a to the main face 30 b.The through electrode 52B is an electrode that electrically connects theemitter terminal 112 to the ground terminal 412B and that passes throughthe mounting substrate 30 from the main face 30 a to the main face 30 b.

Here, the through electrode 51B is not composed of one substantiallycylindrical via electrode extending from the main face 30 a to the mainface 30 b and has a structure in which multiple substantiallycylindrical via electrodes are connected in series to each other in themounting substrate 30. The through electrode 51B has a structure inwhich multiple substantially cylindrical via electrodes are connected inseries to each other in the resin member 40B. The planar wiring patternsalong the respective layers are formed between the multiplesubstantially cylindrical via electrodes in the mounting substrate 30.

In a plan view of the main face 30 b from the main face 30 a, thesubstantially cylindrical via electrodes adjacent to each other in theZ-axis direction are at least partially overlapped with each other inboth the mounting substrate 30 and the resin member 40B. In other words,no path in the XY plane direction only through the planar wiring patternexists in the through electrode 51B and the path in the Z-axis directionexists in the through electrode 51B. The through electrode 52B has thesame structure as that of the through electrode 51B.

With the above configuration, the emitter terminal 111 is not limitedlyoverlapped with the ground terminal 411B in the above plan view due tothe through electrode 51B and it is possible to increase the degree offreedom of the arrangement of the ground terminal 411B. In addition, theemitter terminal 112 is not limitedly overlapped with the groundterminal 412B in the above plan view due to the through electrode 52Band it is possible to increase the degree of freedom of the arrangementof the ground terminal 412B. Furthermore, for example, the size(diameter) of the multiple substantially cylindrical via electrodes maybe changed and multiple substantially cylindrical via electrodes may beprovided in the same layer to enable further decrease of the thermalresistance on the heat radiation path.

In the embodiment, the example, and the modifications described above,although the through electrode passes through not only the mountingsubstrate 30 but also the resin member 40B, the through electrode may beformed across the main face 30 a and the main face 30 b and the throughelectrode may be connected to the external connection terminal on themain face 30 b. For example, in the cross-sectional view of theradio-frequency module 1A illustrated in FIG. 3A, among the throughelectrodes 51 and 52, the portions formed in the mounting substrate 30may be the through electrodes and the portions formed in the resinmember 40B may be the external connection terminals, which are membersdifferent from the through electrodes.

In other words, the radio-frequency module according to an embodiment ofthe present disclosure may include a mounting substrate 30 which hasmain faces 30 a and 30 b and in which radio-frequency components arecapable of being mounted on the main faces 30 a and 30 b, a PA 11mounted on the main face 30 a, a through electrode that is connected tothe PA 11 and that passes through the mounting substrate 30 between themain face 30 a and the main face 30 b, and an external connectionterminal that is formed on the main face 30 b and that is connected tothe through electrode.

With the above configuration, since the circuit components are mountedon both of the mounting faces of the mounting substrate, it is possibleto increase the density and reduce the size, compared with aradio-frequency module using the single-side mounted substrate. Inaddition, since the PA 11 having a high heating value is mounted on themain face 30 a and the PA 11 is connected to the external connectionterminal with the through electrode formed in the mounting substrate 30,the heat radiation path only through the planar wiring pattern havinghigh thermal resistance, among the lines in the mounting substrate 30,is capable of being excluded. Accordingly, it is possible to provide thecompact radio-frequency module having improved heat radiation effectfrom the PA 11 to the external substrate 90.

The external connection terminal may be, for example, a substantiallycolumn-shaped electrode that is arranged on the main face 30 b and thatextends in a normal direction of the main face 30 b in the resin member40B.

The external connection terminal may be a bump electrode arranged on themain face 30 b. In this case, the resin member 40B is not arranged.

The external connection terminal may be connected to the externalsubstrate.

In a plan view of the mounting substrate 30, the through electrode maybe at least partially overlapped with the external connection terminal.

With the above configuration, since the PA 11 is capable of beingconnected to the external connection terminal with a substantiallyminimum distance and the thermal resistance on the heat radiation pathfrom the PA 11 is capable of being decreased, it is possible to furtherimprove the heat radiation effect from the PA 11 to the externalsubstrate 90. In addition, since the area in which the externalconnection terminal is formed at the main face 30 b is capable of beinglimited to an area almost immediately below the PA 11, it is possible toincrease the area in which the circuit component mounted on the mainface 30 b is formed. Accordingly, the degree of freedom of thearrangement of the circuit component is improved.

Other Embodiments and so on

Although the radio-frequency modules and the communication apparatusaccording to the embodiments of the present disclosure are describedabove, the radio-frequency module and the communication apparatusaccording to the embodiments of the present disclosure are not limitedto the embodiments described above. Other embodiments realized bycombining arbitrary components in the above embodiments, modificationsrealized by making various changes supposed by a person skilled in theart to the above embodiments without departing from the spirit and scopeof the present disclosure, and various devices including theradio-frequency module and the communication apparatus are also includedin the present disclosure.

For example, in the radio-frequency modules and the communicationapparatus according to the embodiments described above, other circuitelements, lines, and so on may be provided between the paths connectingthe respective circuit elements and the signal paths disclosed in thedrawings.

The present disclosure is widely usable for a communication device, suchas a mobile phone, as a radio-frequency module arranged in a multibandfront end unit.

While preferred embodiments of the disclosure have been described above,it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the disclosure. The scope of the disclosure, therefore, isto be determined solely by the following claims.

What is claimed is:
 1. A radio-frequency module comprising: a mountingsubstrate having a first face and a second face, which is opposed to thefirst face; a transmission power amplifier mounted on the first face,the transmission power amplifier including an emitter terminal; anelectrode connected to the emitter terminal of the transmission poweramplifier, wherein the electrode passes through the mounting substratebetween the first face and the second face; a ground terminal connectedto the electrode; a low noise reception amplifier mounted on the secondface; a transmission filter mounted on the first face; and a receptionfilter mounted on the first face, wherein in a plan view of theradio-frequency module in a direction vertical to the first face and thesecond face, the transmission filter is arranged between thetransmission power amplifier and the reception filter.
 2. Theradio-frequency module of claim 1, wherein the radio-frequency module isconnected to an external substrate, and the ground terminal is connectedto the external substrate.
 3. The radio-frequency module of claim 1,further comprising: first resin formed on the first face that covers atleast part of the transmission power amplifier.
 4. The radio-frequencymodule of claim 3, further comprising: second resin formed on the secondface that covers at least part of the low noise reception amplifier. 5.The radio-frequency module of claim 4, wherein the ground terminal isarranged on the second resin.
 6. The radio-frequency module of claim 5,further comprising: a ground electrode layer formed of a planar wiringpattern in the mounting substrate; and a first shield electrode layerformed to cover a top face and side faces of the first resin andconnected to the ground electrode layer at side faces of the mountingsubstrate.
 7. The radio-frequency module of claim 5, further comprising:a second shield electrode layer formed on side faces of the second resinand connected to the ground electrode layer at the side faces of themounting substrate.
 8. The radio-frequency module of claim 1, wherein ina plan view of the radio-frequency module in a direction vertical to thefirst face and the second face, a footprint of the electrode at leastpartially overlaps with a footprint of the ground terminal.
 9. Theradio-frequency module of claim 1, wherein in a plan view of theradio-frequency module in a direction vertical to the first face and thesecond face, a footprint of the transmission power amplifier does notoverlap with a footprint of the low noise reception amplifier.
 10. Theradio-frequency module of claim 1, wherein in a plan view of theradio-frequency module in a direction vertical to the first face and thesecond face, a footprint of the low noise reception amplifier at leastpartially overlaps with a footprint of the reception filter.
 11. Theradio-frequency module of claim 1, wherein in a plan view of theradio-frequency module in a direction vertical to the first face and thesecond face, a footprint of the low noise reception amplifier mounted onthe second face at least partially overlaps with a footprint of thereception filter.
 12. A radio-frequency module comprising: a mountingsubstrate including a first face and a second face, which opposes thefirst face; a transmission power amplifier arranged on the first face;an electrode connected to the transmission power amplifier and thatpasses through the mounting substrate between the first face and thesecond face; and an external connection terminal arranged on the secondface and connected to the electrode; a low noise reception amplifiermounted on the second face; a transmission filter mounted on the firstface; and a reception filter mounted on the first face, wherein in aplan view of the radio-frequency module in a direction vertical to thefirst face and the second face, the transmission filter is arrangedbetween the transmission power amplifier and the reception filter. 13.The radio-frequency module of claim 12, wherein the radio-frequencymodule is connected to an external substrate, and the externalconnection terminal is connected to the external substrate.
 14. Theradio-frequency module of claim 12, wherein in a plan view of theradio-frequency module in a direction vertical to the first face and thesecond face, a footprint of the electrode at least partially overlapswith a footprint of the external connection terminal.
 15. Acommunication apparatus comprising: an external substrate; and aradio-frequency module comprising a mounting substrate having a firstface and a second face, which is opposed to the first face; atransmission power amplifier mounted on the first face, the transmissionpower amplifier including an emitter terminal; an electrode connected tothe emitter terminal of the transmission power amplifier, wherein theelectrode passes through the mounting substrate between the first faceand the second face; and a ground terminal connected to the electrode; alow noise reception amplifier mounted on the second face; a transmissionfilter mounted on the first face; and a reception filter mounted on thefirst face, wherein in a plan view of the radio-frequency module in adirection vertical to the first face and the second face, thetransmission filter is arranged between the transmission power amplifierand the reception filter.
 16. The communication apparatus of claim 15,wherein in a plan view of the communication apparatus from a directionvertical to the first face and the second face, a footprint of theexternal ground electrode at least partially overlaps with a footprintof the electrode.
 17. The communication apparatus of claim 15, whereinthe radio-frequency module is connected to an external substrate, andthe ground terminal is connected to the external substrate.
 18. Thecommunication apparatus of claim 15, wherein the radio-frequency modulecomprises a first resin formed on the first face that covers at leastpart of the transmission power amplifier.